1. Field of the Invention
This invention relates generally to a valve arrangement for a beverage dispenser in which a diluent is mixed with a syrup, and more specifically, this invention relates to a valve arrangement for a beverage dispenser in which carbonated water is mixed with a concentrate for dispensing at a relatively fast rate.
2. Description of the Prior Art
It is desirable that a beverage dispenser discharge the beverage as quickly as possible. However, there are limitations on the rate at which it is desirable to discharge the beverage. For example, if the beverage is dispensed at too high a rate it can splash from the cup or other container into which it is directed. Also, if the container is filled too rapidly it can overflow with the attendant waste of beverage.
However, the most significant limitation on the dispensing rate of a beverage formed by mixing carbonated water with a concentrate is the foaming that can occur. As carbon dioxide is released from solution in carbonated water, the introduction of the concentrate results in foaming of the beverage in the cup. This will either result in overflowing of the cup or in the customer getting a very small portion of the beverage after the foam has dissipated. In most cases, there would be an overlapping of these two effects. Further, the resulting drink after foaming would tend to be flat.
The foaming becomes a problem when a relatively high flow rate is utilized because changes in the direction or size of the carbonated water flow path create greater pressure drops then when a slower flow rate is used. The earlier in the flow path that a pressure drop is experienced, the more time there is for the carbon dioxide to come out of the water. Therefore, it is desirable to have as much of the pressure drop as possible occur immediately prior to mixing of the carbonated water with the concentrate.
Prior attempts to provide a higher dispensing rate have utilized a series of orifices to reduce the pressure prior to mixing of the carbonated water with the concentrate. While the pressure can be reduced in this fashion, the velocity of the carbonated water and the mixed beverage is still very high with the attendant problems. Therefore, relatively slow flow rates have been utilized in prior art beverage dispensers.